No one can look into this man's heart for you and determine his true feelings and motives. You just have to trust your heart and your instincts. You say he treats you well and you understand each other well. So what is the reason for your doubt or suspicion? Has he done something to make you suspicious?

If your only reason for being suspicious is because he is from Morocco, then you are not being just or fair to him. Allah tells us in the Quran not to suspect one another, because surely some suspicion is a sin. Not every young man from a poor country is a manipulative visa seeker. I mean, let's be honest, it's quite likely that he does want to get a visa, because life in Morocco is hard and he would have more opportunities in the UK. But that does not mean that he does not also love you and care for you, or that he is not sincere in his intentions.

There are some other issues that you need to consider, however:

1. Why are you keeping this secret from your parents? That's not the right move. They need to be brought into the matter, so they can talk to the man, and talk to his parents, and get everything out in the open in order to proceed. Otherwise, what is your plan? To marry him secretly? Face it, at some point you need to bring your parents into it. Might as well do it now.

2. I don't know your cultural background. But presumably you grew up in the UK. I hate to generalize, but I have to tell you sister that most Moroccan man are very controlling of their women, and can be very jealous and possessive. I have warned sisters about this more than once, and they ignore my warnings, and either the marriage turns out to be a disaster, or the men gradually cut the women away from their families and friends and isolate them within the marriage. I'm not saying these men are bad (except for one, who is a wife-beater - he is bad). But there is a cultural gulf, and for women who have grown up in the West, it can be very frustrating.

You need to question him specifically about your future relationship with your family and friends, how he would feel about you working or studying, etc. You must have a clear understanding of the boundaries before you proceed, even it means putting things in writing.